Flared exit phlebotomy needle



Patented May 19, 1953 UNITED A srAres fear ori-'ice l v l 2,638,897

FLARE!) :PHLEBOTGMY NEEDLE Edward J. mums, mindedness. Application J al1-nary 18, 1951,-Serial'No,206,599

f Mir-'present invention relates generally to .neefdlesand more specifcallyto hypodermic needles fior' subcutaneous injections and for piercing -puncturable closures in `the collection and administration of parenteral, intravenous, landftlde 'likesurgical iiuids, #and especially blood. More -particularly 'the-invention'provides .a new and -i'nfipromed needle assemblywhich .is .designed to minimize `clotting -in fllood `letting :and infusing pr'actice, and which isv adapted particularly -for use with1 vflexible plastic and the like ,conducting and storing elements permitting the sterile ideterioration-freeA handling of lWhole blood. I The 'nature yand characteristic features .of my invention will be better understood irom the folzlowingfdescription .taken in vconjunction withL the 'accompanying `drawings which illustrate :by way fof example preferred embodiments, and in-whicn-z Fig; .l is anelevational yiewoi one fneedle;

Fig. 2 lis a longitudinal sectional .View .of the asame; I Fig. 3 fis an expanded 1 sectional .View showing fthe dared fendof 4the. needle insert;

FigAii's'a View similarto Fig. 3.0i an alternative -formrof the needle;

Fig. 5 is an end elevation, looking at the pointed lfend 1of the needle;

. Fig. 6is'an elevation'looking yat vthe end distal -'to the point;

Fig. 7 is a View jlikezthat Vof Fig. .1, showing a protective sheath V:and .a fragmentary section of @flexible vtubing installed Aat l'the opposite sides of `themanipulating,portion; f

Fig. 8 :is a .fragmentary section -or' a.-coupling exemplary of fprior construction, :indicating vthe l *flow of 'the fbl'ood at' the junctureof the needle --andthebloodconductingIelementand Fig. `9 iis :a `similarvieil/of 'a coupling incorporating 'my-novel lila'red exit needle.

' The apparatus employed yheretoforel vintloe ,handling o'ffmedic'al and surgical vfluids lhas' been .Sieur-1d 'deficient in one .for more -of ticenumerous- "characteristics for "properties required vlior the Esteri-le collectionandinfusion and the coagula- "tion-'f-ree and -degra'dation-retardving storage yof UWhole blood. in. such phleb'o'tozny practice, -blood contacting elements of the apparatus must fbe `dashiened nl :fa readily sterilized material 'which :lends itself to va ftechfni'c by'whichft'he 'blood fis llient sealedei'i firomfcontac't the'atmo'sphere,

which isicliaraeteized by'fainon-Wettable imper- 'frneable' fsurfacafand-wliich at ileast i in the.: case .of .thefblood'lconduetingiandlstoring .elementssisrnex- 'able zand'fcollapsiblezto .fardegreesubstantially e1im inating liquid gas interface between the bloedend :the 'retaining wall.

feclaims. (cLizs-cai) Prior `blood Aletting and infusingneedles in particular, incorporating'- come rnonl;r ,or `trequently vafiemale lnulo coupled to the associated rblood .conducting tubing through an yinterimediate adapter, have militated against 4the ain-tight assembly varmi sterile handlingand storage .required of such apparatus. More impor.- tantly the-use of the I rientioned adapter .andalSo the uniformly ey1indrica1 -bore common .to such prior needles lhave prevented .a smooth ltransition v:fronfr-tlie lumenf ftheneedle 60 lthe tubing, thus giving frise to unwanted. .clotting Yof the 4blood at .the coupling.

yBy the present invention there Iis :provided a Hotel needleassembly capable of general application', but providingparticularly the characteristics mentioned "as required vier leest phlebotomypractice. In par-ticulanniynovel needle will 'be seen :to haveaa coupling element adapted to be seized directly toztlfiebloodconducting 7tuloing .in an airtight mannerfand otherwiseracilitating thesterile handling of the needland also .a lumen `fash- -gioned specially to minimize clotting of the blood :in tneregion ofthe coupling.

Referring new 'to the .drawings in greater de.-

xtail. the .needle 1s-indicated generally at A. Aand .comprises fa relatively .rigid tube `or cannula Hl,

preferably Qffstal'llesssteel, which 'has asmooth landfgenerally vuniform lumen or lbore I I extending uninterruptedly .throughout its entire length toprQmote-laminarflow ofthe 4lolood. and to facilitate cleaning. The cannula may be manufactured in'any desiredsze,-asforfexample 15 gauge.

a eine causing minimum 1nhysidlogic disturbance to a donor `and thus found desirable in phlebotemr. er itfmey :,-be yfor further example i9 gauge. which jisasize permitting a desired rate of -iiow ,for infusion purposes. The' cannula VIi! -will be fcutforgroundobliquely atene end to form a-piercing .or pnncturing point 4,2 in :known manner.

s lier.ein'leeore :mentioned desired anti-coagulant and `clot-free handling of blood as .for exampie Vin Iphlelootomy practice has been hampered heretofore .by disturbance of the'ow of theblood :at the .coupling v.of 4:the 4blood-letting needle with .the :blood conducting 1tube. fSuch clot-forming :disturbance or interterence Withfsmoot'h laminar row is ,understood to result from the lsharp break .oramore `particularlythe annular shoulder in the will be understood that the fiat-faced end wall and the iiow eddying cavity formed adjacent thereto are characteristic of prior structures irrespective of whether the coupling is direct to the needle or through an adapter as mentioned. Thus Fig. 8 may be regarded as representative of the ycoupling of a needle proper, or of either end of such adapter with the associated blood conducting element, in the prior practice.

The needle of the present invention is novelly constructed and arranged at the end remote from the piercing tip to minimize and substantially preclude the described interference with the laminar iiow of the blood, irrespective of the direction of such ilow. More particularly, the needle bore is formed with a gently flaring, conical enlargement, as indicated generally at C` in Figs. 3 and Ll. Such conical flare is seen to be convergent with the oppositely tapering coupling hub 22 (to be described hereinafter), and to merge there- 'with at the end of the needle to define a relatively thin-walled, annular rim, which is rounded, as shown, to eliminate altogether the cavity-forming right-angular flat-faced construction heretofore mentioned. I have found a flare of about 10 taper and proportioned and arranged to reduce the needle wall thickness at the rim to about 0.020 to be eminently satisfactory in use. As indicated particularly in Fig. 9, the described needle bore flare smoothly shapes and guides the flow of the blood into the sometimes larger or different diametered blood conducting element, and the associated end of such conductor, expanded as shown over the mentioned needle coupling hub, desirably hugs and contracts about the described rounded end Wall of the needle so as substantially to eliminate the cavity mentioned as previously characterizing the region of the coupling. 'Ihus the probability of clotting at the coupling end of the needle commonly experienced velement 20 of the needle is rigidly and permanently mounted on the cannula at the end distal -to the point l2 in any convenient manner, as by sweating or fusing. Such element may be of metal, which may be the same as or similar to that of the cannula IIJ, or a more easily machinable metal or alloy such as a brass with chrome plating. In the preferred form, however, it has a plastic composition, as for example nylon, which lends itself to the desired hermetically sealed, firm-gripping engagement with-the associated blood conducting tube. It is here noted also that a coupling element fashioned of a slightly compressible plastic, such as nylon, effects an excellent seal with the relatively incompressible socket of other units such as a syringe tube, sharpening ixture, and washing device, to which the needle may be coupled.

This cannula surrounding element 20 as shown comprises an intermediate manipulating body 2| of four-sided or other outside contour, preferably non-round, merging oppositely into aligned tapered conical coupling hubs 22, 23, which are dimensioned to t within and seize to the open end of flexible tubing t of standard proportions, as indiacted in Fig. 7. Hub 22, at the end remote from the needle point and over which the tubing or other resilient tubular element is fitted when the apparatus is assembled for use is somewhat longer and of a atter taper than hub 23, as shown, to provide additional tube anchoring sur- 4 face and especially secure inter-gripping action. 'Ihe distinctive functions of the respective hubs in this regard will more fully appear hereinafter. Where the coupling and manipulating element 20 is formed as preferred of a plastic such as nylon molded directly about the cannula I0, a more secure interconnection of the two members is obtained by fashioning the element 20 with a portion overlying the end of the cannula l0. In such case this molded element 20 is itself also formed with an internal flare 24, Figs. 2 and 3, substantial-ly continuous with and also exactly conformant to cannula flare I3. Thus in the preferred embodiment of Fig. 3 the joint between the cannula l0 and manipulating element 20 is internal at the exit or tube connecting end of the A needle.

Where alternatively a metallic coupling element 20a is employed, Fig. 4, manufacturing convenience is served by terminating it flush with the cannula 'Illa at the exit end of the needle. In such instance the flared portion of the cannula is extended as shown at 13al to maintain the dcsired lumen surface configuration and needle wall thickness. It will be apparent that with the embodiment of Fig. 4 as with the preferred form of Fig. 3 the tube-gripping surfaces of the coupling element are uninterrupted, the joint between element 20a. and cannula Illa being located in the vlike reduced and rounded end wall. The needles of Figs. 3 and 4 may be identical in other constructional respects, providing commonly and importantly the lumen flare already described.

To maintain the needle in a sterile, protected condition ready for use the cannula is enclosed in a sheath 40, shown in Fig. '7, placed over the cannula and seized to the shorter hub 23. 'I'he relatively short length and steep taper of hub 23 makes for easier removal of the sheath. It is noted that an entire blood handling apparatus may be kept in a sterile condition by sealing the free ends of the blood conducting tubes with my novel needle, in the manner just described. While the describedv double hub and coupling portion 20 of the needle performs satisfactorily as to tube-gripping and sealing action when of a metallic construction, as in Fig. 4, for best results, more particularly a still firmer, hermetically sealed coupling with the flexible plastic tubing t, it is fashioned of nylon or a like plastic material, as recited for the preferred embodiment of Fig. 3.

Where the needle is to form part of apparatus designed to prevent or ldelay coagulation and degradation of the blood, the cannula desirably is treated with a medium which furnishes with respect to blood a non-wetting bore lining or lm to prevent clotting of the blood passing therethrough. For this purpose a substantially monomolecular anti-coagulant lm is applied from a dilute (0.1 to 1%) aqueous dispersion of such substance as exemplified by either dicocodimethyl ammonium chloride or octadecyl primary amine. Alternatively, the cannula itself may be fashioned of nylon or such other synthetic resin as possesses the desired toughness While presenting sterilizable chemically clean, inert, and non-wettable surfaces to the blood.

'Upon assembly with the sheathing and/or tubing or other tubular connection the needle and accompanying apparatus are placed in condition for use by sterilizing by any technically acceptable method, as for example by subjecting it to a temperature of not less than C. for a continuous period of at least thirty minutes.

My novel needle is shown in the ready-foruse condition in Fig. 7. It will be obvious that it may be readily manipulated by grasping element at the gripping portion 2i. The needle is placed in use merely by removing the protective sheath 40, as facilitated by the shorter and steeper conical hub 23 as contrasted with the other hub 22 and the retention oi its grip with the tubing, and applying the needle to the donor or recipient as required. rlhe smooth and uninterrupted cannula bore of lumen promotes the desired laminar ow of the blood at a rate determined by the needle gauge. The longer and ilatter conical hub 22 insures a secure, airtight coupling with the associated tubing section, adapted to be maintained under all conditions of use. And as importantly and novelly provided by the present invention the lumen exit nare i3, 24 promotes and preserves a smooth transition from the needle to such tubing section, thereby substantially reducing and minimizing the likelihood of coagulation or clotting at the coupling.

From the foregoing it will be readily appreciated that by my present invention the sterile and deterioration-free collection, storage and administration of parenteral fluids and particularly of Whole blood, is made possible with a needle assembly adapted particularly for use with apparatus having blood protecting and preserving characteristics, but having general utility in phlebotomy, blood administering and other practice where a hypodermic needle is required.

My invention is not limited to the exemplary embodiments herein illustrated or described, and I set forth its scope in my following claims.

I claim:

1. A new and improved anti-coagulant hypodermic needle adapted directly and sealingly to be coupled to a blood conducting member, said needle comprising a rigid cannula having opposite pointed and non-pointed ends, said cannula defining and extending continuously over substantially the full length of the needle, an elongate coupling and manipulating element directly concentrically surrounding an intermediate portion of the cannula and the adjoining non-pointed end thereof, said cannula having a laminar flow promoting lumen of generally uniform diameter but formed at the non-pointed end with a gently flaring enlargement of the opening reducing the wall thickness of the needle at said end and also guiding and controlling the ilow of the blood for minimum disturbance in the region of the coupling whereby clotting of the blood thereat is substantially eliminated.

2. A needle according to claim 1 wherein the lumen wall carries an anti-coagulant nlm.

3. A new and improved anti-coagulant hypodermic needle comprising a coupling and manipulating element including a sleeve formed at one end with a tapered coupling hub adapted for seizing reception in a flexible tubular bloodconducting element, and surrounded thereby a relatively rigid cannula pointed at the end remote from said hub and formed with a lumen of generally uniform diameter but flaring at the coupling end thereof, whereby a smooth transition from said cannula to such bloodconducting element is effected and clot-forming disturbance of the now of the blood in the region of the coupling is minimized.

4. A needle according to claim 3, wherein the coupling and manipulating element is of a synthetic resin molded onto the cannula and formed with a portion extending beyond the coupling end of the cannula and having a lumenforming inner wall substantially continuous with and tapering conformant to said flared exit end thereof.

5. A needle according to claim 3, wherein the coupling and manipulating element is of metallic construction, and is terminated liush with the cannula at the coupling end of the said needle.

6. A coupling according to claim 3, wherein the hub and lumen converge terminally to form a relatively thin walled rounded rim about which the connective element contracts to present a blood-conducting passage substantially continuous with said lumen.

EDWARD J. POITRAS.

References Cited in the i'lle of this patent UNITED STATES PATENTS Number Name Date 600,803 Robinson et al. Mar. 15, 1898 1,100,181 Hart June 16, 1914 1,109,626 Davis Sept. 1, 1914 1,139,975 Hopper May 18, 1915 2,217,602 Smith Oct. 8, 1940 2,504,482 Goldman Apr. 18, 1950 FOREIGN PATENTS Number Country Date 574,278 France Mar. 27, 1924 

